Elastic fluid turbine



June 3, 1941. YF, H, KNOWLTON, JR A2,244,398

ELAsTIc FLUID TURBINE Filed Sept. 30, 1938 ,mw n J, y m m i www 0. 5.. mja .E VKA F 2 .WW 3 a L P w Patented June 3, w41

'FT T ELASTIC FLUID TUR-BENE Paul H. Knowlton, Jr., Schenectady, N. Y., assignor to General Electric Company, a, corporation of New York 8 Claims.

This invention relates to elastic uid turbines and more particularly to arrangements for redirecting the elastic fluid through the turbine after having once passed through the wo-rking passage thereof.

In elastic fluid power plants, an auxiliary turbine may be connected in series with a main turbine as for driving the boiler auxiliary ap.- paratus. Such auxiliary turbines are usually of a single stage type and are so connected in series as to have inherent self-regulating characteristics. Since the quantity of operating fluid flowing therethrough is proportional tothe load on the main turbine, the speed of the auxiliary turbine and hence of the boiler auxiliaries will be maintained in substantial accordance with the boiler demand. During no-load conditions of the main turbine or during periods of low boiler output, the eiiiciency of the auxiliary turbine may be irnproved by the provision of means for redirecting I the new of operating uid through the bucket wheel stage a second or more times. Such redirecting means, however, will ordinarily seriously impair the efliciency of the auxiliary turn are provided for redirecting the operating fluid through the turbine during periods of reduced flow and which means are excluded from the path of the operating fluid during periods of maximum flow.

A further object of my invention is the provision of an improved elastic fluid power plant arrangement in which an auxiliary turbine connected series ahead of a main turbine or oonsumer may be eiiiciently operated during low load and no load condition ofthe main turbine or consumer.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appendcd thereto taken in connection With the accompanying drawing.

Referring to the drawing, Fig. l represents a side elevation, partly in section, of an elastic iluid turbine embodying my invention; Fig. 2 is a cross-sectional view of Fig. 1 taken along the line 2 2; Fig. 3 is a fragmentary cross-sectional view of Fig. 1 taken along the line 3-3 illustrating certain details; Fig. 4 is a side elevation, partly in section, of an elastic fluid turbine illustrating a modication oi' the invention; and Fig. 5 illustrates diagrammatically an elastic fluid power plant embodying my invention.

Referring to Figs. 1 and 2, the elastic uid turbine I is provided with a valve chest I I having a plurality of valves I2, I3 and I4 arranged therein for regulating the flow of elastic fluid from the source of supply through conduit I5 to the various sectional admission nozzle chambers I6, Il and I8 of the turbine. The turbine is shown in this instance as having a single stage bucket wheel I9 mounted upon the shaft 2B which may be connected to any suitable load such as the boiler auxiliary apparatus (not shown). After passing through the bucket wheel, the elastic fiuid is received in the exhaust chamber ZI of the turbine and conducted to the main turbine or to any after-connected-elastic fluid consuming apparatus (not shown) through the outlet 22.

The admission controlling valves I2, I3 and Iii may be of any suitable type and are shown diagrammatically as being biased to the closed position as by spring means 23, 2li and 25 respectively. The valves are adapted to be actuated to the opened position by means of a cross bar 26 connected'to an operating rod 2l. In the case of turbines designed for series operation, the valves are usually regulated in accordance with the demand for operating fluid by the after-connected steam consuming apparatus. As indicated, the stops on the valve stems are so graduated that they are engaged by the cross bar and the valves moved to the opened position in sequential order. During a period of low demand for operating fluid by the the after-connected apparatus, only the valve I2 Will be in an opened position for passing the operating iiuid through the iirst nozzle section I 6. In the event that the auxiliary turbine is connected to a load requiring a certain minimum of power even during periods of reduced boiler output, such as the boiler auxiliaries, the reduced iiow of operating iiuid passing once through the bucket wheel may be insulcient for carrying the load. According to my invention, when only the rst admission valve I2 is opened, the operating fluid passed therethrough is redirected to pass through the bucket wheel stage a second time to impart additional energy thereto. A redirecting device B is slidably arranged within suitable guides SI provided within the housing section 32. The redirecting device 3D, shown more clearly in Figs. 2 and 3 may comprise a block having a reversing passage 33 therein for receiving the operating fluid passed through the bucket wheel from the nozzle chamber IB and directing it back through the bucket wheel stage at another point. One or more varies 34 may be provided in the passage to assist in turning the steam flow through the requisite angle. Upon passing through the bucket wheel stage the second time, the operating fluid is received within a chamber 35 which conducts the exhaust fluid back into the exhaust chamber 2| through a passage 36 communicating therewith below the lower periphery of the bucket wheel. The redirecting device 30 is normally biased to its lowermost or operative position by spring means 3l acting through the control rod 38 connected therewith. As the supply of operating fluid through the auxiliary turbine is increased and the need for redirecting the operating fluid through the auxiliary turbine no longer exists, provision is made for automatically withdrawing the redirecting device from the operative position. As indicated, an extension 39 of the valve lifting cross bar 25 is adapted to engage with a stop on the stem. 38 for moving the redirecting device from the operative position substantially simultaneously with the opening of the valve I3. In order that the regulation of the auxiliary turbine be not too greatly disturbed, the redirecting device is gradually moved from the operative position preferably at the same rate of speed as the opening movement for the valve I3. While by the diagrammatic arrangement shown, the redirecting device is withdrawn from the operative position at the identical rate of the vopening movement of the valve I3, it is understood that by any suitable cam arrangement welleknown in the art the speed and the timing of the withdrawal of the redirecting device 3! may be adjusted as desired.. It will be noted that, as shown in Fig. 2, the lower wall of the redirecting device is tapered as at lill so that the flow of operating fluid emerging from the bucket wheel after the nozzle section I6 will not be unduly ob structed during the withdrawal thereof.

In Fig. 4 is illustrated a second modification of the invention in which the turbine 45 is provided with a plurality of sectional admission valves 46-l9 inclusive, controlling the admission of elastic fluid from the valve chest G to the nozzle sections 5I54, inclusive. In this modi cation, the elastic fluid redirecting device 55 is lxedly arranged to receive the operating fluid passed through the first valve 46 and through the nozzle section 5I and return it through the bucket wheel stage a second time. In this instance the valves may be controlled as by a bar having cams 56-59, inclusive, for engaging cooperating rollers on the stems of the Valves ltd-JIS, inclusive. The arrangement of the cams is such that the valves are actuated to the opened position in sequential order. When the valve 46 is in the opened position, during the no-load flow of elastic fluid through the system, the flow passing through the first nozzle section 5I is redirected through the bucket wheel stage to maintain a high efficiency of the turbine during this period. As the elastic fluid demand is increased and the cam bar actuated to the left, the second valve 41 is moved to the opened position. As the flow of elastic fluid is still further increased, the valve 48 is opened and simultaneously the roller of the valve 46 will be dropped from the cam 56 to close that valve. During the increased flow of operating fluid through the system, when the need of redirecting elastic fluid through the bucket Wheel no longer exists, the full flow of operating fluid is passed through the remaining admission nozzles lll- 49 inclusive depending upon the station demand. By the proper arrangement and design of the valve operating cams, the closure of the first valve ahead of the redirecting device may be effected at the proper time and rate in accordance with the load on the auxiliary turbine.

An elastic fluid power plant arrangement according to my invention as shown in Fig. 5 comprises a main turbine or consumer 60 for driving a generator 6I and an auxiliary turbine 62 for driving power plant auxiliaries 53. The auxiliary turbine 62 is connected in series ahead of the main turbine 60 by a conduit 64 and the fluid flow through both turbines 62 and 60 is controlled by valve means corresponding to valves I2, I3, I4 of Fig. 1. The auxiliary turbine 62, as explained above, includes a fluid flow reversing device and means for rendering such device inoperative as the rate of fluid flow to the auxiliary turbine increases beyond a certain value.

Having described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. In an elastic fluid turbine, valve means for regulating the flow of operating fluid therethrough, control means for said valve means, means for redirecting the elastic fluid through said turbine when said valve means are adjusted for a predetermined minimum flow therethrough and means controlled by said valve control means for rendering said redirecting means inoperative upon said valve means being adjusted for a predetermined increased flow of operating fluid therethrough.

2. In an elastic fluid turbine, valve means for regulating the flow of elastic fluid to said turbine, means operative upon a predetermined minimum quantity of elastic fluid being passed through said valves for redirecting such quantity through the turbine, and means for rendering said redirecting means inoperative upon an amount greater than said predetermined quantity f elastic fluid being passed through said turbine.

3. In an elastic fluid turbine having a plurality of sectional admission valves` means for adjusting said plurality of valves to the opened position in sequential order, means for redirecting the elastic fluid through said turbine from the flrst of said sectional admission valves, means for rendering said redirecting device inoperative upon the adjustment of predetermined other sectional ad mission valves to the opened position.

4. In an elastic fluid turbine having a plurality of sectional admission valves adapted to be adjusted to the opened position in sequential order, means for redirecting operating fluid through the working passage of said turbine, means normally biasing said redirecting device to the oper ative position, and means for gradually shifting said redirecting device to the inoperative position simultaneously with the adjustment of a predetermined sectional admission valve to the opened position.

5. In an elastic fluid turbine having a plurality of sectional admission valves, means for adjusting said plurality of valves to the opened position in sequential order, means for redirecting through the turbine the elastic fluid passed through the first of. said sectional admission valves, and means for shifting said redirecting device to an inoperative position simultaneously with the adjustment of a second of said sectional admission valves tothe opened position.

6. In an elastic uid turbine having a plurality of sectional admission valves, means for redirecting through the turbine the ow of elastic iluid passed through the rst of said sectional admission valves, and means for shifting said redirecting device to an inoperative position upon a second of saidv sectional admission valves being moved to the opened position.

7. In an elastic fluid turbine having a plurality of sectional admission valves, means for adjusting said plurality of valves to the opened position in sequential order, means for redirecting through the turbine the elastic uid passed through the rst of said sectional admission valves, and means for closing said rst valve upon the adjustment of a predetermined later valve to the opened position.

8. In an elastic iluid turbine having a plurality of sectional admission valves, means for adjusting said plurality of valves to the opened position in sequential order, means for redirecting through the turbine elastic fluid passed through the rst of said sectional admission valves, and means for moving said first valve to the closed position upon a predetermined number of succeeding valves being moved to the opened position.

PAUL H. KNOWLTON, JR. 

